Bernhard muller



j UNITED STATES PATENT OFFICE.

BERNHARD MULLER, OF CHEMNITZ, GERMANY.

PROCESS OF MAKING BRICKS FROM COAL-DUST.

SPECIFICATION forming part of Letters Patent No. 526,936 dated October 2, 1894.

Application filed July 7,1892. Serial No. 439,287. (No specimens.) Patented in Germany April 12, 1892, No- 70,481; in France May 20, 1892,110. 221,785; in England May 24,1892. No. 9,854, and in Belgium June 8, 1892 No. 100,051.

To all whom it may concern.-

Be it known that I, BERNHARD MiiLLER, a subject of the German Emperor, residing at Ohemnitz, in the Kingdom of Saxony and Empire of Germany, have invented a new and useful Improvement in Processes of Making Pressed-Goal Briquets, (for which I have obtained Letters Patent in England, No. 9,854, dated May 24, 1892; in France, No. 221,785, dated May 20, 1892; in Belgium, No. 100,051, dated June 8, 1892, and in Germany, No. 70,481, dated April 12, 1892,) of which the following is a specification.

The refuse or residuum arising in the mining, lifting, digging and separating of pitcoal consists of a mixture of coal-dust and small pieces of coal which cannot be usually employed in the ordinary furnaces of industrial establishments, because the refuse is too small and drops through the grates of said furnaces, or is easily blown away when artificial draft is employed. It also burns too quickly and d oes not give the required steady heat, besides having other disadvantages and drawbacks.

The object of this invention is to furnish an improved process of making coal briquets from coal dust, and the invention consists in making such briquets by molding into blocks the coal dust containing from five to twelve per cent. of water and from one to three per cent. of tar, said molding operation being performed at a temperature from 40 to centigrade and under a pressure of not less than eight hundred kilograms, the bitumen or tarry matter being brought to the surface of the coal and the separate particles made to adhere to each other thereby.

The processes heretofore used for the man ufacture of compact coal have the following disadvantages, to wit:

First. That the small coal had to be very highly heated. A complete chemical alteration thereof was thereby effected, the carbureted hydrogen and the. bitumen being melted and masses of a coky nature produced which are capable for use to some extent for fuel; but for chemical purposes, as for example the manufacture of gas, they are useless. Moreover the tarry products are entirely lost.

Second. In order to bind the small coal a large addition of pitch was necessary, and the product was thus rendered very expensive,

as the cost of the binding material was con- N siderable.

Third. The molded bodies so produced were neither ready for use noradapted for transportation until after they had been kept in a drying chamber and baked for the purpose of hardening them.

Apart from the considerable increase of price occasioned by the processes mentioned, the gases developed by the process of drying the briquets have a most penetrating and offensive smell, which makes the carrying out of the process in any populated district obnoxious. The tar and oil-products are also by these processes entirely lost.

Allof these defects are altogether obviated by my invention according to which- First. The small coal need only be subjected to a temperature of not under 40 and not over 70 centigrade.

Second. The tar or pitch addition for the binding of the coal-particles is entirely omitted in the case of coal rich in bitumen, while in the case of inferior coal one to three per cent. of tar is added for thepurpose of increasing the resistance of the coal briquets to the action of water and the weather.

It is clear that this decrease of temperature and dispensing with the addition of tar, or reduction in the amount thereof, must be compensated for by other means, as otherwise only brittle and quickly perishable briquets would be obtained. This compensation is effected as follows:

First. The pressure is increased to at least eight hundred kilograms.

Second. The coal, by moistening or drying, should be allowed to take up or retain respectively not less than five per cent. and not more than twelve per cent. of water.

It is only by the co-operative action of the three above mentioned .factors-namely: first, a temperature of 40 to 70 centigrade;

' second, a pressure of over eight hundred k ilograms, and, third, a moisture of from five to twelve per cent. of the 'coal--that the fluid matter, oily and tarry matter, or bitumen, can be pressed out of the pores of the coal so as to unite the small particles of coal together so that they do not afterward fall to pieces.

For the practical application of the process therefore the small coal must contain from portation and applicable to the same purposes as coal from the pit.

I claim as my invention- 1. The process of making coal briquets which consists in molding into blocks bituminous coal dust, containing from five to twelve per cent. of water, under an abnormally high pressure of not less than eight hundred kilograms, and under an abnormally low temperatureof from 40 to 70 centigrade, the bituminous matter, under the high pressure and the moisture, exuding from the pores of the 25 coal particles and serving to compactly unite them together, while owing to the low temperature, the mass remains wholly in an uncoked condition, substantially as set forth.

2. The process of making coal briquets, 30 which consists in mixing with coal dust containing from five to twelve per cent. of water, one to three per cent. of tar, and molding said mass into blocks under an abnormally high pressure of not less than eight hundred kilo- 5 grams and underan abnormally low temperature of from 40 to 7 0 centigrade, the oily and tarry matter under the high pressure and the moisture serving to compactly unite the coal particles, while owing to the low temperature, 40.

the mass remains wholly in an uncoked condition, substantially as set forth.

In witness whereof I have hereunto set my hand in presence of two witnesses,

BERNHARD MULLER. Witnesses:

R. E. J AHN, EUGEN A. FRAISSINET. 

